Doors don't fit right, help?

[xDiesel]

I have a 1969 GMC K20. I am trying to do a quick sort-of restoration, mostly body work and just fixing problems. Right now the cab and front end are stripped down and I'm trying to fix some rust and holes, and there is a rather large dent on the roof by the passenger door. It broke one of the cab lights and it looked like it may have bent the framing around the door, which was my first guess as to why the door didn't fit. But the problem I am having is that both doors don't really fit right even by just holding them up in place with no hinges or anything, the top front corner of both doors is touching while the back has a nice gap and I can't twist the door to make it fit right. And both doors a new, from different trucks, and they have no rust or dents. I measured the door frames and they seem to be the same. Any ideas as to why they won't fit?